The Center for Addiction and Pregnancy (CAP) is a specialized multi- disciplinary treatment program developed to address the treatment needs of pregnant drug dependent women. However, many women drop out of treatment prematurely and relapse to substance use, placing both mother and infant at increased risk for adverse outcomes. Beginning in 1994, as a component of a NIDA-funded treatment center grant, behavioral research procedures were integrated into ongoing clinical practice at CAP and a series of voucher incentive studies were conducted to improve treatment participation and reduce substance use. The current proposal builds upon and expands this research. Specifically, it compares the effectiveness of alternative voucher incentive methodologies for reinforcing drug abstinence in pregnant drug dependent women and examines clinical and economic benefits of such incentive programs for both mother and infant. One large (N=420) study is proposed with two experimental and one control condition. The study will compare the relative efficacy and utility of two voucher payment schedules to a yoked control condition. The two voucher conditions will include: 1) an escalating schedule, designed to promote long periods of continuous abstinence and widely employed in research conducted to-date, and (2) a simpler-to implement constant rate schedule that provides a fixed monetary payment for each drug-free urine,a nd that may be equally effective. In addition to assessing the effects on retention and drug use, the study will examine secondary benefits of the incentive procedures on: participation in individual and group counseling, compliance with prenatal care services, and maternal and infant clinical outcomes (e.g., birthweight, EGA at delivery, Apgar scores, medical complications) as a function of treatment condition and drug use outcomes. The study will also provide valuable information about voucher incentive effects in women who are assigned (based on clinical characteristics) to methadone maintenance versus abstinence-based (non-methadone) therapy during CAP treatment participation. Since pregnant drug dependent women and their children are at increased risk for a variety of adverse outcomes that requires expensive medical care, improved maternal and infant clinical outcomes are likely to produce substantial medical cost savings which could easily offset the monies invested in voucher payments. Study finding swill be of interest to both treatment providers and managed care organizations as they can easily be adopted for use in a variety of treatment settings.